NFL free agency started Wednesday at 4 p.m. ET with the new league year kicking off, and a flurry of deals agreed to during the legal tampering period Monday and Tuesday became official as a result.

Free agency isn't always the best place to build a Super Bowl-caliber team; just look at the New England Patriots, who rarely spend big on marquee free agents and still consistently contend each season.

However, for teams with glaring roster weaknesses and tons of salary cap space, acquiring a star player or two definitely can lay the foundation to contend for a playoff spot (and possibly more).

With those things in mind, let's take an early look at the winners and losers of NFL free agency so far.

Winner: Patriots free agents

Winning a Super Bowl and playing well in New England continues to be a money maker for Patriots free agents. Several Pats players cashed in this week, even though many former New England stars who've left Bill Belichick in free agency haven't played at that same high level for their new teams.

Here's a look at the Patriots players who earned a nice chunk of money this week:

Winner: Oakland Raiders

The Raiders' overhaul this offseason looks pretty good so far.

They traded for elite wide receiver Antonio Brown in a deal with the Pittsburgh Steelers that didn't cost Oakland any first-round picks. The Raiders also addressed a huge need at left tackle by agreeing to sign Patriots starter Trent Brown to a four-year, $66 million contract. Oakland agreed to sign safety Lamarcus Joyner to improve a lackluster secondary as well. On Wednesday, the Raiders agreed to sign Los Angeles Chargers wide receiver Tyrell Williams, adding another top-tier target for quarterback Derek Carr and weakening a division rival at the same time.

The Raiders still have three first-round picks in next month's 2019 NFL Draft.

Don't be surprised if the Raiders are a trendy pick to compete for a playoff spot in the AFC next season, especially if they do well in this draft.

Winner: Detroit Lions

Matt Patricia's first season as Detroit Lions head coach ended poorly with a last-place finish in the NFC North. Next year looks like it'll be better, though, after the Lions added the top free agent available in Patriots defensive end Trey Flowers, in addition to veteran wide receiver Danny Amendola and veteran cornerback Justin Coleman in free agency. Flowers and Coleman should help a Lions defense that struggled quite a bit last season, while Amendola gives franchise quarterback Matthew Stafford a dependable target on third downs and in the red zone.

Loser: Pittsburgh Steelers

The Steelers acquired just third- and fifth-round draft picks, as well as no salary cap relief, from the Raiders in exchange for Antonio Brown (arguably the league's top wide receiver). Pittsburgh also wasn't able to re-sign star running back Le'Veon Bell, and there are no running backs on the free agent market capable of adequately replacing him. The Steelers haven't added any key pieces to a defense that was mediocre last season, either.

Could we finally be seeing the end of the Steelers' run as a top contender in the AFC? It sure looks like it.

Winner: Nick Foles

Being the best unrestricted free agent quarterback was a great situation for Nick Foles, who cashed in by signing a four-year, $88 million contract with the Jacksonville Jaguars. Foles went from being a backup, to leading the Philadelphia Eagles to a Super Bowl LII win over the New England Patriots, to now getting $50 million in guarantees as the undisputed starter in Jacksonville. Oh, and did we mention he has a statue outside Lincoln Financial Field in Philly?

Winner: Green Bay Packers

The Packers ranked 22nd in points allowed, 22nd in rushing yards allowed, 19th in turnover differential and just weren't able to get enough key stops on defense when it mattered most.

As a result, we saw a rare strategy from Green Bay: spend big in free agency.

The Packers added linebackers Preston Smith (four years, $52 million) and Za'Darius Smith (four years, $66 million), as well as safety Adrian Amos (four years, $37 million) to help fix a mediocre to below-average defense. Amos' addition also hurts the Packers' biggest rival and top competitor in the NFC North division, the Chicago Bears.

Franchise quarterback Aaron Rodgers might not be under so much pressure to score a ton of points next season.

Loser: Washington Redskins

The Redskins made a huge splash to sign safety Landon Collins from the rival New York Giants, but the cost was six years and $84 million (including a whopping $45 million guaranteed). Collins is a really good player, but that money could have been spent a little more efficiently elsewhere.

Washington has many other roster holes, including at wide receiver after Jamison Crowder left in free agency to join the New York Jets, as well as linebacker after Preston Smith left for the Green Bay Packers.

Winner: Cleveland Browns

The Browns completed a blockbuster trade with the New York Giants to land superstar wide receiver Odell Beckham Jr., which will give quarterback Baker Mayfield a top-tier receiving duo in Jarvis Landry and OBJ. Cleveland also bolstered its defense by acquiring veteran linebacker Olivier Vernon as part of the OBJ trade, and by adding veteran defensive lineman Sheldon Richardson on a free-agent contract.

The Browns almost made the playoffs last season, and these moves, plus whatever they add in the 2019 NFL Draft, should put them in a strong position to compete for the AFC North crown in 2019.

Loser: New York Giants

The Giants acquired three solid assets for Odell Beckham Jr. (2019 first- and third-round picks, plus safety Jabrill Peppers), but their offense should take a huge step back without the talented wide receiver. The worst part of the Beckham trade for the Giants might be the $16 million in dead cap space being wasted because of this deal. In fact, New York has the most dead cap money ($33.8 million) of any team next season, as of this writing. This money could have been used to improve the team's many roster weaknesses that must be addressed.

New York will have to lean heavily on second-year running back Saquon Barkley in 2019, so his usage will be something to monitor next season. Could the extra carries and targets wear him down and increase the risk of injury?

The G-Men also lost star safety Landon Collins in free agency and valuable linebacker Olivier Vernon as part of the OBJ trade with the Browns, hurting an already poor defense. Oh, and by the way, Eli Manning remains the starting quarterback.

Loser: Buffalo Bills

The Bills tried to trade for superstar wide receiver Antonio Brown but couldn't pull it off, so they instead overpaid to add veteran wideouts Cole Beasley (four years, $29 million) and John Brown (three years, $27 million). These aren't bad additions, but they also don't make the Bills' passing attack a lot more intimidating than it was last season. Buffalo's backfield also consists of veterans Frank Gore (signed this week) and LeSean McCoy, who are 35 and 30 years old, respectively.

Agreeing to sign Kansas City Chiefs center Mitch Morse is a great addition for Buffalo, but it's hard to see the Bills contending for a playoff spot at the moment.

Loser: Baltimore Ravens

The Ravens lost several key pieces of their defense from last season, a unit that gave up the second-fewest points in the league.

Here's a look at the important departures from Baltimore's elite defense:

C.J. Mosley, LB: signed with New York JetsEric Weddle, S: released by RavensPreston Smith, LB: signed with Green Bay PackersTerrell Suggs, DE: signed with Arizona Cardinals

Sure, the Ravens signed safety Earl Thomas, and if healthy, he'll add a veteran presence and plenty of talent to their secondary. But they gave him a four-year, $55 million contract when he's already 29 years old and has a recent history of injury.

The Ravens did well to add New Orleans Saints running back Mark Ingram in free agency, but he's unlikely to be a huge difference maker. The bottom line is Baltimore needs young quarterback Lamar Jackson to take a huge leap in 2019 because it's hard to imagine the defense being as dominant as it was last season.